Technical Field
The present invention relates to an apparatus for ejecting liquid.
Description of the Related Art
In an apparatus that ejects liquid using a liquid ejection head, a technique of forming dots of a plurality of sizes by applying a plurality of driving pulses (ejection pulses) to a pressure generator in time series, by continuously ejecting a plurality of droplets, and by integrating a plurality of droplets during flight.
Conventionally, for example, there has been a configuration in which a driving waveform including a first driving pulse and a second driving pulse supplied to a pressure generator of a recording head in time series is generated and output within a single driving cycle. The first driving pulse at least includes a pull-in waveform element for expanding individual liquid chambers, and a push-in waveform element for contracting the expanded individual liquid chambers. The second driving pulse at least includes a pull-in waveform element for expanding the individual liquid chambers, and a push-in waveform element for contracting the expanded individual liquid chambers. The time from the end point of the push-in waveform element of the first driving pulse to the start point of the pull-in waveform element of the second driving pulse is an integer multiple of the natural vibration period of the individual liquid chambers.
Meanwhile, when driving a liquid ejection head in which a plurality of nozzles is arranged, if nozzles (meaning of nozzles for ejecting liquid) simultaneously driven increase, there is a problem of occurrence of difference between the ejection velocity of liquid ejected from the nozzle of a central portion of the nozzle row and the ejection velocity of liquid ejected from the nozzle of an end of the nozzle row, due to pressure interference and pressure fluctuation in the common liquid chamber.